Electromagnetic apparatus.



APPLIOATI N0 MODEL.

WITNESSES.

PATENTED DEC. 6, 1904.

J. N. MAHONEY.

ELECTROMAGNETIC APPARATUS.

0N FILED MAR.19.X904.

2 SHEETS-SHEET 1.

FTE. 2

INVENT If ATTORNEYS.

No. 777,039. PATENTED DEC. 6, 1904. J. N. MAHONEY.

ELECTROMAGNETIC APPARATUS.

' APPLIOATION FILED MAR.19, 1904.

N0 MODEL. 2 SHEETS--BHIET 2v WITNE88E8: INVENT R fl TTORNEVS NITEDSTATES Patented December 6, 1904.

JOSEPH N. MAHONEY, OF BROOKLYN, NElV YORK.

ELECTROMAGNETIC APPARATUS- SPECIFICATION forming part of Letters PatentNo. 777,039, dated December 6, 1904.

Original application filed January 21, 1904, Serial No. 190,061. Dividedand this application filed March 19, 1904. Serial No. 198,982. (Nomodel.)

To all whom it vii/my concern:

Be it known that I, JosnPH N. MAHONEY, a citizen of the United States,residing in the borough of Brooklyn, county of Kings, State of New York,have invented certain new and useful Improvements in ElectromagneticApparatus, of which the following is a specification.

This invention is shown in the form of a tractive electromagnet designedto perform work-as, for instance, in an electromagnetic car-brake systemto apply the shoes to the wheelsand is illustrated in connection withmechanical appliances whereby the pressure between the braking-surfacesso obtained or the strain exerted by the magnet may be re tained bymechanically-acting locking devices which, according to the requirementsof any system to which such an electromagnet may be applied, may bereleased, as desired, either automatically or otherwise.

The invention, as will be apparent to those skilled in the art,isapplicable to many uses, and that shown is merely illustrative of oneuse to which the invention may be applied either with or without thelocking or retaining devices.

.ln the accompanying drawings, Figure 1 is a vertical section on theline 2 2 of Fig. 2. Fig. 2 is a front elevation of the same, the stop orbu flier bar shown in Fig. 1 being, how ever, omitted. Fig. 3 is a sideelevation, partly broken away to show a detail of the retainingmechanism; and Fig. 4c is an end elevation.

The apparatus comprises an outer body or shell a, of magnetic metal,which may be castiron, and within which are disposed the bobbins orwindings 6, three bobbins being shown in this instance, each having twowindings b I). O1 course the winding of the apparatus will be adapted tothe purpose intended and may consist of wire of unequal gage and lengtharranged in any desired way. lNithin the bobbins is a bushing 0, ofnon-corrosive and non-magnetic metal such, for instance, as copper orbrass--and within this tube or bushing reciprocates the armature orplunger Z,of superior magnetic metahsuch as wroughtiron or cast-stcel.The rear head oi the shell, which may also be of. cast-iron, carries ahollow polepiecef, of wrought-iron or caststeel. that extends within thewinding. The bushing 0 extends, preferably, from the polepieecf to thefront opening in the shell. The bore of the polc-picccfis of the shapeof the flUStUl'Il of a cone, the smaller diameter of which is at theouter end, and the inner end oi the plunger or armature (Z is conical,with the same angle of taper as that of the bore in the pole-piece, butof greater length. The purpose of so shaping the pole-piece and end ofthe armature is to decrease the area of the air-gap relatively to thedecreasing length of the air-gap as the armature moves inward. This isaccomplished by permitting the tapcred end of the armature to passbeyond the outer or smaller end of the opening in the pole-piece,thereby tending to maintain a constant reluctance in the magneticcircuit, and consequently a uniform pull throughout the travel of thearl'nature. This arrangenumt alsoincreascs the general cllicicncy ofapparatus of this character by increasing the area of the air-gaprelatively to the cross-section of the area of the armature.

Attached to the Front or outer end of the armature is the jaw or clcvis1 provided with pin 7' for attachmentot' the part onwhich the pull ofthe armature is to be exerted. The rear plate or end piece a is formedwith an opening a for passage of the wires and preferably covered by ahood (9. A segmental stop or retaining plate 71 bolted to the trout endof the shell and serves to hold the bushing c in position. In Fig. l lhave shown a stop or butter for limiting the outward movement of thearmature. It consists of three arms attached at the three threadedopenings vi v1" v1 and connected with or uniting in a head or buffer 1?,against which abuts the clcvis or jaw g or any other part that may beprovided projecting from the plunger.

The upper face of the armature is flattened, and resting thereon is anangular or L-shaped shoe located between the shell and a block k, boltedto the front face and extending inwardly into a chamber k, formed in thefront of the shell. A steel roller m (or one or more steel balls) liesloosely within the angle of the shoe and is normally urged inwardly bytwo pins n, acted upon by coiled springs seated in sockets in the block7:. Resting on the roller is a Wedge-block 0, which in the constructionshown is normally presseddownwardly on the roller by a cam 39, attachedto or forming part of a shaft q, relatively mounted in bearings q (1. Tothis cam-shaft is secured a leverarm 1-, against which bears a plug 5,seated in a casings and normally urged forwardly by a coiled spring 8adjustment of the spring being afforded by means of a screw 8 working inthe head or end of the casing s.

The strain of the load or the reactionary pull of the brake-gear in abraking system would on cessation of or suflicient diminution of currentin the windings retract the armature were it not that the roller m bearsupon the inclined face of the wedge-block, which is positively held bythe cam, thereby pressing the shoe j against the flattened face of thearmature and locking it against withdrawal. This locking of the armaturemay be released in any appropriate way, either automatically orotherwise. The organization illustrated, however, contemplates itsrelease automatically by passage of current through the windings of amagnet u which may be of the same general construction as the magnetalready described and on the side of the shell of which it may bemounted. The armature or plunger '26 of this release-magnet is normallyretracted, permitting the plunger .9 to hold the wedge-block in contactwith the locking-roller; but when current passes in the coils of therelease-magnet and its armature is attracted the lever-arm r, with whichit is connected by apin-and-slot connection 10 or otherwise, is drawnforward to rock the shaft 9 and carry the rise of the cam 12 away fromthe upper surface of the wedge-block 0, thereby unlocking or releasingthe armature (Z, the wedgeblock then being free to rise. Of course thelocking-roller might rest directly on the flattened upper face oftheplunger or armature (Z; but I prefer to employ a shoe having al'lat facebearing on the flattened face of the armature, as the shoe may bereplaced in the event of wear thereof and danger of the flattened faceof the armature being injured is obviated.

This is a division of my application, Serial No. 190,061, filed January21, 1904, for electric brakes for vehicles.

I claim as my invention- 1. An electromagnet comprising a winding and ashell of magnetic metal inclosing it, a pole-piece projecting within thewinding and having through it an opening with inclined walls, and anarmature reciprocable within the winding and having its inner endtapered to conform to the taper of the opening in the pole-piece but ofsuch length as to extend through and beyond it.

2. An electromagnet comprising a winding and a shell of magnetic metalinclosing it, a pole-piece projecting within the winding and havingthrough it an opening with inclined walls, an armature reciprocableWithin the winding and having its inner end tapered to conform to thetaper of the opening in the pole-piece but of such length as to extendthrough and beyond it, a wedge-block, a roller interposed between it andthe side of the armature, a spring device normally urging the roller outof engagement with the inclined face of the wedge-block, and means forforcing the wedge-block against the roller to thereby lock or retain thearmature in any position to which it may be attracted.

3. An electromagnet comprising a winding and a shell of magnetic metalinclosing it, a

pole-piece projecting within the winding and having through it anopening with inclined walls, an armature reciprocable within the windingand having its inner end tapered to conform to the taper of the openingin the pole-piece but of such length as to extend through and beyond it,a wedge-block, a roller interposed between it and the side of thearmature, a spring device normally urging the roller out of engagementwith the inclined face of the block, a rocking shaft carrying a cambearing on the wedge-block, a spring tending to force the wedge-blockdown on the roller and an electromagnet acting in opposition to thespring.

4. An electromagnet comprising a winding, an armature reciprocablewithin the winding, a wedge-block, a locking-roll interposed between itand the armature, means for normally urging the inclined face of theblock against the roll to lock the armature in its attracted position,and means for releasing the pressure of the block upon the roll topermit retraction of the armature.

5. An electromagnet comprising a winding, an armature reciprocablewithin the winding, a wedge-block, a locking-roll interposed between itand the armature, means for normally urging the inclined face of theblock against the roll to lock the armature in its attracted position,and an electromagnet acting to release pressure of the block upon theroll to permit retraction of the armature.

6. An electromagnet comprising a Winding, an armature reciprocablewithin the Winding, a wedge-block, alocking-roll and shoe in which it isseated interposed between the side of the armature and the inclined faceof the Wedgeblock, means for normally urging the inclined face of theblock against the roll to lock the armature in its attracted position,and means for releasing the pressure of the block upon the roll topermit the retraction of the armataper of the opening in the pole-pieceand ture. adapted to extend through it. I

7. An electromagnet comprising a winding In testimony whereof havehereunto suband a shell of magnetic metal inclosing it, a scribed myname.

5 pole-piece extending within the winding and JOSEPH N. MAHONEY.

having an opening with inclined Walls, and an Witnesses: armaturereciproeable within the winding and CLARENCE M. LEWIS,

having its inner end tapered to conform to the LILLIE F. BROWNING

